Metastatic Cancer to Bone.

Metastatic disease to bone is the most common malignancy of bone. The American Cancer Society estimated that in 2004 there will have been 1,368,030 new cases of cancer in the United States.1 Of these, they estimated that approximately 2,400 will be new cases of primary bone malignancy; that is, compared with over 230,000 new cases of prostate carcinoma, 217,000 cases of breast carcinoma, and 173,000 cases of lung carcinoma. Those three diagnoses, along with kidney cancer and thyroid carcinoma, represent 80% of metastases to the skeleton.2 Autopsy studies have shown that 50% to 70% of patients with prostate cancer develop metastases and 85% of patients with breast cancer develop skeletal metastases. The skeleton is surpassed only by the lungs and liver for incidence of metastatic disease. Any bone of the skeleton can be involved; however, the axial skeleton is most commonly involved. Involvement of the appendicular skeleton most commonly involves the proximal portion of the lower extremities. Within the spine, it is primarily the anterior and middle columns that are involved. [ABSTRACT FROM AUTHOR]